When electric equipment is installed in an environment where the equipment is available for the use of an unspecified number of users, it is generally required to have security features for preventing theft and the stealing of information.
In order to prevent the theft of electric equipment, for example, electric equipment can be fastened to a desk or the like with a chain, a wire, etc so as not to move beyond a certain distance from its installation location.
Besides, in order to prevent the stealing of information, a password can be assigned to electric equipment so that users who do not know the password cannot use it. For the same purpose, a device for authenticating users (e.g. card reader) can be connected to or installed in electric equipment.
However, even if the electric equipment is fixed with a chain, a wire, etc., it can be stolen by cutting the chain. In addition, the electric equipment needs to have a configuration for attaching a chain or a wire on its body, which imposes limits on the design of the exterior of the equipment.
Moreover, even when a password is assigned to the electric equipment or information, if the password has leaked out to a user who is not authorized to access the information by, for example, “over shoulder cracking” or “shoulder hacking”, the user can steal the information through an unauthorized access.
Further, a user who intends to steal information can find out the password by a “brute force attack” or “brute force password cracking” if he/she has enough time. A person who has a good knowledge of electric equipment and passwords can choose a password others will not be able to guess. However, a password which is difficult to find out is ultimately a complex password containing many digits, and users who are not quite accustomed to electric equipment would find it difficult to use such password. Even a person who set a password can forget the password and lose access to the electric equipment.
Still further, electric equipment and a system employing the electric equipment command a higher price when a user-authenticating device such as a card reader is connected to or installed in the electric equipment. Additionally, it is sometimes difficult to install a user-authenticating device in a small-scale system adopting a PDA (Personal Digital Assistant).
As described above, sufficient measures have not been taken to prevent the theft of electric equipment and the stealing of information.
As an example of the prior art for increasing the security of a computer system, Japanese Patent Application laid open No. HEI10-49493 discloses “Computer System”. In the computer system according to the prior art, a computer and peripheral devices are provided with nonvolatile memories, respectively, for registering identification numbers. When one peripheral device is connected to the computer, the computer obtains a registration number from the connected peripheral device, and determines whether or not the registration number matches that of the computer. The computer allows a user the use of the peripheral device only when the two numbers match.
The above-mentioned computer system, however, is aimed at preventing the stealing of the peripheral devices connected to the computer. That is, in the above-mentioned computer system, the computer makes the peripheral devices nonusable when registration numbers obtained from them do not match the registration number of the computer. In other words, the computer system is not aimed at preventing the theft of electric equipment and the stealing of information.